Recently, rapid development in information technology (IT) has greatly affected the automobile industry, and IT and communication technologies have been combined with a vehicle.
In particular, recently released vehicles include various wireless communication functions for communication with an external device. In this way, various application services have been provided.
For example, a route guidance device such as a navigation system is a significantly useful device that assists a driver in identifying a location of a road on which the driver is currently driving or in easily locating a destination when the driver drives in an unfamiliar area by positioning a current location of a vehicle based on a signal received through a global positioning system (GPS) satellite, reading map data corresponding to the positioned current location from an incorporated map database, and displaying the map data on a screen together with the current location of the vehicle.
In addition, recently released vehicles include various in-vehicle communication networks for exchanging information among various controllers included in the vehicle and diagnosing conditions thereof.
In particular, most recently released vehicles include various vehicle safety systems and driver convenience systems. Accordingly, the amount of data transmitted and received in an in-vehicle communication network has rapidly increased.
Therefore, in a current trend, a gateway has been applied to midsize and full-size cars to balance communication load. In addition, a rapider communication scheme such as a controller area network (CAN) with Flexible Data rate (CAN-FD), Ethernet, etc. has entered advanced development in preparation for communication load to be increased in the future.
A diagnostor for vehicles communicates with a controller according to a diagnostic communication standard (for example, including ISO15765-2) for diagnosis, compulsory driving, reprogramming, etc. of controllers included in a vehicle. In this instance, the diagnostor and the controller for vehicles may be routed through a gateway for vehicles.
For example, a CAN communication scheme may be used as the in-vehicle communication network. In this case, a CAN frame may be used as a diagnostic message.
A CAN frame for diagnosis may be divided into a single frame in which a size of a transmission block does not exceed 8 bytes and consecutive frames in which a size of a transmission block exceeds 8 bytes and thus the transmission block needs to be transmitted in several segmented CAN frames.
Referring to the consecutive frames, a receiving end transmits, to a transmitting end, information about a data block size (BS) of data blocks to be received through the consecutive frames and a transmission period of the consecutive frames for the data blocks, that is, a value of Separation Time Min (STMin) through a flow control frame.
However, BS and STMin values applied to a conventional controller for vehicles have been previously defined and used based on a size of a memory installed in the controller, CPU performance, etc. at the time of developing the controller. Therefore, there has been a problem in that data loss occurs and thus a diagnostic communication error is generated when load of an in-vehicle network intermittently and abruptly increases or overflow of bus capacity occurs.
Moreover, the BS and STMin values applied to the conventional controller for vehicles have been preset based on performance of a separate controller without considering a real-time condition of network load, and thus have not been dynamically changed in response to addition/deletion/change of the controller in the vehicle and real-time variation in network load. Therefore, there has been a disadvantage in that diagnosis and reprogramming time could not be optimized.